United States Consumer Price Index (CPI) is a price index constructed monthly by the U.S. Bureau of Labor Statistics that provides a statistical measure of the average change in prices in a fixed market basket of goods and services. It is frequently called a cost-of-living index, however, it is not a complete cost-of-living measure.
Effective with the January 2007 release, index levels are published to three decimal places. Percent changes based on these three-decimal place indexes will continue to be published to one decimal place. Previously published indexes will not be revised.